As the end of the night drew near, Followill promised the audience that he would sing something that hadn't been performed at any of their previous shows. It would be a challenge, he said, because they didn't have any band members that could play piano. "We've asked our friend to come help us out," he told the audience before introducing Coldplay's Chris Martin.

The crowd erupted. Martin, with a brief wave to the audience, sat himself at the keyboard and quickly launched in to "Talihina Sky" and then "Notion."

And just like that, Martin exited stage left as quickly as he arrived. Followill cracked, "We hope you enjoyed that. It cost us a lot of money."

And while this reporter soaked in the beautiful sounds of the performance, our eyes were immediately scanning the audience for a Jennifer Lawrence sighting. After all, she did travel to Las Vegas to support her new man at the iHeartRadio Music Festival just last month. Why wouldn't she make it a date night at this gorgeous (and local) Los Angeles venue?

According to Just Jared, J.Law did just that. The site reports that the Hunger Games star "playfully" engaged with her new beau during rehearsals, even recording photos and videos of his performance on her phone. An unnamed source also reportedly claims that "Martin Lawrence," as they've been dubbed, even kissed on the lips "several times" during rehearsal.

Well, ETonline was backstage before the show for an interview with show openers Young the Giant (more on that soon!) and saw no signs of J.Law. We'll take this as a valuable life lesson: one must always have eyes peeled for Jennifer Lawrence. Always!!!